Debande%smd.ucl.ac.be@cunyvm.cuny.edu (Benoit Debande) (03/14/91)
Hello,
In a previous UNIX-DIGEST, rob@sswax1.dnet.loral.com made a (long) mail about
using DNS and /etc/hosts with SUNOS 4.1
I followed his 2nd solution (based upond the sources of BIND) and applied
his modification to allow host lookup first by DNS and then on /etc/hosts.
This is the first patch enclosed : it replaces
resolver.patch/gethostnamadr.c.patch
included in the file "bidon41.shar"
But, I'm not fully satisfied with the order of looking, and I prefer looking
first in /etc/hosts and then by DNS. ie: that allows me to use local aliases
for hosts.
So, I made another modification to the sources, and it is the second patch
enclosed.
It also replace the original one from the file "bidon41.shar".
I hope it will help ....
===============================================================================
Dr. Benoit DEBANDE E-MAIL : debande@smd.ucl.ac.be
School of Medicine debande@buclln11.bitnet
Catholic University of Louvain FAX : 32-2-7645322
Av. Hippocrate 50 (50.20) PHONE : 32-2-7645268
B-1200 BRUXELLES (BELGIUM)
===============================================================================
Theory : it doesn't work an you know why
Practice : it works an you don't know why
C programming : it doesn't work and you don't know why
===============================================================================
FISRT ENCLOSURE : rob's modification patch
*** gethostnamadr.c.orig Thu Jan 4 19:25:13 1990
--- gethostnamadr.c Wed Mar 13 18:57:33 1991
***************
*** 40,49 ****
static char hostbuf[BUFSIZ+1];
static struct in_addr host_addr;
static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf = NULL;
static char hostaddr[MAXADDRS];
static char *host_addrs[2];
! static int stayopen = 0;
char *strpbrk();
#if PACKETSZ > 1024
--- 40,49 ----
static char hostbuf[BUFSIZ+1];
static struct in_addr host_addr;
static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf;
static char hostaddr[MAXADDRS];
static char *host_addrs[2];
! static int stayopen;
char *strpbrk();
#if PACKETSZ > 1024
***************
*** 261,270 ****
if (_res.options & RES_DEBUG)
printf("res_search failed\n");
#endif
- if (errno == ECONNREFUSED)
return (_gethtbyname(name));
- else
- return ((struct hostent *) NULL);
}
return (getanswer(&buf, n, 0));
}
--- 261,267 ----
***************
*** 293,301 ****
if (_res.options & RES_DEBUG)
printf("res_query failed\n");
#endif
- if (errno == ECONNREFUSED)
return (_gethtbyaddr(addr, len, type));
- return ((struct hostent *) NULL);
}
hp = getanswer(&buf, n, 1);
if (hp == NULL)
--- 290,296 ----
SECOND ENCLOSURE my modification patch
*** gethostnamadr.c.orig Thu Jan 4 19:25:13 1990
--- gethostnamadr.c Wed Mar 13 18:47:49 1991
***************
*** 40,49 ****
static char hostbuf[BUFSIZ+1];
static struct in_addr host_addr;
static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf = NULL;
static char hostaddr[MAXADDRS];
static char *host_addrs[2];
! static int stayopen = 0;
char *strpbrk();
#if PACKETSZ > 1024
--- 40,49 ----
static char hostbuf[BUFSIZ+1];
static struct in_addr host_addr;
static char HOSTDB[] = "/etc/hosts";
! static FILE *hostf;
static char hostaddr[MAXADDRS];
static char *host_addrs[2];
! static int stayopen;
char *strpbrk();
#if PACKETSZ > 1024
***************
*** 217,222 ****
--- 217,223 ----
register char *cp;
int n;
extern struct hostent *_gethtbyname();
+ struct hostent *hp;
/*
* disallow names consisting only of digits/dots, unless
***************
*** 254,272 ****
}
if (!isdigit(*cp) && *cp != '.')
break;
! }
! if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0) {
#ifdef DEBUG
if (_res.options & RES_DEBUG)
printf("res_search failed\n");
#endif
! if (errno == ECONNREFUSED)
! return (_gethtbyname(name));
! else
! return ((struct hostent *) NULL);
! }
! return (getanswer(&buf, n, 0));
}
struct hostent *
--- 255,275 ----
}
if (!isdigit(*cp) && *cp != '.')
break;
! }
! if (( hp = _gethtbyname(name)) != NULL)
! return(hp);
!
! if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0)
#ifdef DEBUG
if (_res.options & RES_DEBUG)
printf("res_search failed\n");
#endif
! return ((struct hostent *) NULL);
!
! else
!
! return (getanswer(&buf, n, 0));
}
struct hostent *
***************
*** 287,292 ****
--- 290,297 ----
((unsigned)addr[2] & 0xff),
((unsigned)addr[1] & 0xff),
((unsigned)addr[0] & 0xff));
+ if ((hp =_gethtbyaddr(addr, len, type)) != NULL)
+ return(hp);
n = res_query(qbuf, C_IN, T_PTR, (char *)&buf, sizeof(buf));
if (n < 0) {
#ifdef DEBUG
***************
*** 293,301 ****
if (_res.options & RES_DEBUG)
printf("res_query failed\n");
#endif
! if (errno == ECONNREFUSED)
! return (_gethtbyaddr(addr, len, type));
! return ((struct hostent *) NULL);
}
hp = getanswer(&buf, n, 1);
if (hp == NULL)
--- 298,304 ----
if (_res.options & RES_DEBUG)
printf("res_query failed\n");
#endif
! return ((struct hostent *) NULL);
}
hp = getanswer(&buf, n, 1);
if (hp == NULL)
--